It has previously been proposed to operate the motor for an automatic pinsetter intermittently, and one such proposed arrangement was until recently commercially available. However, this system operates on the high voltage circuit level of the motor, and requires an extra junction box of substantial size, and heavy power cables, so that the retail cost of the system was several hundred dollars. In addition, the system caused motor burn-out within a relatively short time after the system was installed. Accordingly, rather than saving money by operating the motor intermittently, there was not only a substantial initial cost for the system, but the additional cost of burned-out motors resulting from the use of this supposed economizer, has caused the system to be much more expensive than the energy which is saved. Other similar systems have been proposed, but they have been no more effective than that of the above described system.
Accordingly, a principal object of the present invention is to provide an inexpensive and effective control circuit for the intermittent operation of the pinsetter motor, and a system which will not burn out the pinsetter motor.
In accordance with the present invention, the existing low voltage circuitry in the automatic pinsetter is employed to power a low voltage control circuit and relay, with the output contacts of the electromagnetic relay being employed to operate the high voltage motor circuit. The control circuit includes three parallel switches to operate the relay, with one being energized by the operation of the clutch to initiate operation of the motor, the second being operated by the deck filling mechanism to maintain the relay energized as long as the deck for holding pins associated with the pinspotter is not completely filled, and a third mechanic's bypass switch so that the motor may be turned on regardless of the state of the clutch or the deck. A delay circuit is included to maintain the relay closed and the pinsetter motor operating for a few seconds after the full deck switch has opened, so that the apparatus may complete its cycle.
In accordance with a feature of the invention, the system may be mounted directly within the existing electrical box of the automatic pinsetter and only employs a few low voltage components, so that the cost of the installation is a fraction of the system described above.
With regard to the details of the low voltage circuit, it may include a diode, and one or more storage capacitors and a resistor to form the delay circuit.
In addition, an anti-sparking circuit including a capacitor, or other known anti-sparking circuitry may be coupled across the motor to further assist in preventing burn-out of the motors.
In accordance with another aspect of the invention, instead of an electromagnetic relay, operative at low voltages, a low voltage solid state switch may be employed to control the high voltage motor circuit.
Other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description and from the accompanying drawings.